Liquid-level indicator



July 23, 1940. J; RUDOLF 2,208,817

LIQUID LEEL.- INDICATOR Filed. June 7,. 1938 Patented July 23, 1940 7 LIQUID-LEVEL INDICATOR.

Henry J. G.v Rudolf, Galesburg, Ill., assignor, by direct and mesne assignments, to. The Applied Mechanics 00., Wellesley, Mass., a corporation of Massachusetts Application June "1, 1938, Serial No. 212,267

4 Claims.

This invention relates to liquid-level indicators of the type having a casing adapted to be mounted in a restricted opening in. the top of a tank with a drum or other pulley in the casing, a tape or other cable extending from. the pulley through the aforesaid opening to a float in the tank, and a spring for winding the tape on the drum as the liquid-level rises in the tank, the drum controlling an indicator calibrated in. terms of liquid measure. Owing to the notorious tendency of such devices to get out of order it is desirable. to test the indicators from time to time v to make-sure they are in proper working order.

Objects of the present invention are to provide, in indicators of the type. referred to, test means which is manually operable without removing the indicator from the aforesaid opening and without opening the aforesaid casing, which is accessible for quick and facile testing, which is proof against misuse in such a way as to displace the aforesaid tape from the aforesaid drum, which is simple. and economical in construction, which is durable and reliable in use and which is generally superior to testing devices heretofore proposed.

According to this invention the. test means is kinematically connected to the aforesaid drum, as by acne-way clutch, to rotate the drumv only in the. direction to wind the tape on the drum, whereby the float may belifted from and dropped to the liquid to test the operation of the indicator without the danger of displacement of the tape from the drum incident to manually turning the drum in the opposite direction. Preferably the shaft or axle upon which the drum is mounted is extended outside the casing and the test means comprises a knurled knob or other handle fitted over the outer end of the axle with an annular space between the handle and axle and a spiral spring closely surrounding the axle in the annular space, one end of the spring being anchored to the handle, so that the spring grips the shaft with a snubbing action when the handle is turned in the direction to wind the tape on the drum.

For the purpose of illustration a typical embodiment of the invention is shown in the accom panying drawing in which,

Fig. 1 is an elevation of the device mounted in a tank;

Fig. 2 is an enlarged vertical cross-section;

Fig. 3 is a horizontal section on line 3-3 of Fig. 2; and

Fig. 4 is a section on line 4-4 of Fig. 3.

The particular embodiment of the invention chosen for the purpose of illustration comprises a plug l adapted to thread into an opening in the top of a tank such as shown at 2, a cupshaped casing 3 mounted on the plug by meansv of a strap saddle 4 and bolts 5 and a tube 6' fast in an opening in the plug l with its upper end flanged outwardly over the periphery of an opening in the strap 4, and a cover I telescoping over the open end of the. cup-shaped casing 3,. the cover I having a window 8 through which to read the indication of the indicator inside the casing.

As shown in Fig. 3 the casing is provided with small openings containing eyelet bearings 9 and. ID, the eyelets I0 also serving to hold, the transparent covering 1 I over the window 8. Pivotally mounted in the bearings 9 and ID are two axlesl l3 and I4. Fast to. the axle I3 is a large. drum l5 and fast to the axle 14 are two drums, a-large drum l6 and a small drum I|,. the-latter drum being in alignment with the drum t5. The drums l5 and I! are interconnected by a thin metallic belt I8. the opposite ends of. which are secured to the two dIlJIlS respectively. A coil spring 2'!" surrounds the axle I3 with one end secured. to the drum I 5 as indicated at 22' and the other end 23 engaging the casing, the spring tending to rotate the drum i5 in a counter-clockwise direc-? tion (Fig. 2).

A second tape 24' is wound upon the' periphery of the drum l6 withits free end" extending down wardly through a guide slot 30. in the periphery of the casing 3 and anchored to the heat .25 which carries a valve 21 of cork or'othensuit able material adapted to seat against the lower end of. the tube 6. when the tank is filled; The float, which is preferably formed of wood, has the same square cross-section throughout" its length, whereby the wetted perimeter'of the'float is always the same irrespective of the depth to which the float is submerged in the liquid. Figi 1 shows the float in end elevation and Fig. 2 in side elevation.

The tapes l8 and 24 are preferably formed of beryllium copper which is unique in having all the desirable characteristics for this purpose without any of the disadvantages of other materials. Tapes of beryllium copper may be formed very thinly without danger of breaking or be-' coming permanently deform-ed; they are hardand springy but not brittle and they are noncorrosive.

The pulley l5 carries the dial indications on its front side as indicated in Figs. 1 and 2, these indications preferably being printed on the sheet metal before it is shaped into the form of a cup. As shown in Fig. 3 the drum [6 preferably comprises two cup-shaped sheet-metal parts secured together bottom to bottom, these parts resembling can covers and preferably being formed in the same way.

As shown in Fig. 3 the axle l3 projects through the cover I and a knurled handle 40 is associated with the outer end of the axle, whereby the interior mechanism may be actuated to test the operability of the device. For example, by turning the handle 40 counter-clockwise the float may be lifted above the liquid and then permitted to drop back. If the indicator returns to its former position the operator knows that the device is functioning properly.

According to the present invention the handle is interconnected with the axle l3 so as to turn the axle in one direction only. Thus the float may be lifted and dropped to test the instrument but the drums may not be rotated in the reverse direction, which would unwind and displace the tapes'f'rom'the drums. In the preferred embodi ment thehandle 48 is cup-shaped and a spiral spring closely surrounds the axle in the annularspace between the handle and axle. One endof thespring is anchored to the handle and the, springs pirals along the shaft in the directio'nto grip the shaft when the handle is turned in the direction towind the tape IS on the drum I S thespringturning freely on the shaft when the handle is turned in the reverse direction. Preferably the spring is anchored to the handle so as toremain approximately'in alignment with the handle when the latter is removed from the axle. As shownin Figs. 3 and 4 this is accomplished by extendingone end of the spring outwardly through an opening 42, thence along an annular groove 43 and thence back into the handle through an opening 44, whereby the spring remains approximately coaxial with the handle when the latter is removed from the axle. Thehandle maybe pushed on or pulled ofi the sh'aftmerely by slowly turning the handle clockwise" while pushing or pulling. When the liquid-level in the the float 26 gradually settles downwardly, thereby unwinding the tape. 24 from the drum 1%, turning the drums l6 and H in a counter-clockwise direction. (Fig. 2), winding the tape [8 from the drum l5to the drum l1, and turning the drum [5 in a clockwise direction (Fig. 2) against the action of the springZl. During the rise of liquid-level-the action is reversed, the spring 2| keeping. the tapes taut. Of course the'parts are so correlated that when the float 26 is in the upper'position shown in Fig. 2 the Full indication on the drum I 5 shows through the window 8 and when the float .26 rests on the bottom of the tank the word"Empty shows through the window- V I claim: Y

1. A liquid-level indicator comprising a casing, an :axle journaledin the casing with one end projecting outside the casing, a pulley fast to the axle inside the casing,- a float outside the casing,

tank 2 is falling means for kinematically interconnecting the pulley and float including a cable wound on the pulley, a handlerotatably mounted on said end of the axle, and a spiral spring closely surrounding said axle with one end anchored to the handle to turn the pulley only in the direction to wind the cable on the pulley, whereby the float may be lifted from and dropped to the liquid to test the operation of the indicator without the danger of displacement of the cable from the pulley incident to manually turning the pulley in the opposite direction.

2. A liquid-level indicator comprising a casing, an axle journaled in the casing with one end projecting outside the casing, a pulley fast to the axle in the casing, a float outside the casing, means for kinematically interconnecting the pulley and float including a cable wound on the pulley, a handle surrounding said end of the axle with an annular space between the handle and'axle', and a spiral spring closelysurrounding the axle in said annular space with one end of the spring anchored to the handle to rotate the axle, by a frictional gripping action, only in the direction towind the cable on the pulley, whereby the float may be lifted from and dropped to the liquid to test the operation of the indicator without the danger of displacement of the cable from the pulley incident to manually turning the pulley 'in' the opposite direction. I

3. Aliquid-level indicator comprising acasing, an 'axle journaled in the casingwith one end projecting outside the casing, a float-outside-the casing, means for kinematically interconnecting the axle and float including a pulley and a cable Wound on the pulley, a rotor rotatablymounted on said end of the axle, and a spiral spring close-- 1y surrounding said axle with oneend anchored to the rotor to turn the pulley only in the direction to wind the cable on the pulley, whereby the float may be lifted from and dropped to the liquid to test the operation of the indicator without'the danger of displacement of 'th e'cable from the pulley incident to manually turning the pulley in the opposite direction.

4. A liquid-level indicator comprising a casing, an axle journaled in the casing with one end projecting outside the casing, a float outside'the casing, means for kinematically interconnect ing the "axle and float including a pulley and a cable wound on the pulley, 'a rotor surrounding said end of the axle with an annular space between the rotor and axle, and a spiral spring closely surrounding theaxle in said 'annular space with one end of the spring anchored to the rotor to rotate the axle, by a frictional gripping action, only in the direction to wind the cable on' the pulley, whereby the float may be lifted from anddropped to the liquid to test the operation of the indicator without the danger of displacement of the cable from the pulley incident to manually turning the pulley in the opposite direction. HENRY J. G. RUDOLF. 

